[b]DICTIONARY OF MEDICAL ACRONYMS & ABBREVIATIONS — 5th Ed[/b] [i]Compiled and edited by Stanley Jablonski[/i] PREFACE TO THE FIRST EDITION Acronyms and abbreviations are used extensively in medicine, science and technology for good reason—they are more essential in such fields. It would be difficult to imagine how one could write down chemical and mathematical formulas and equations without using abbreviations or symbols. In medicine, they are used as a convenient shorthand in writing medical records, instructions, and prescriptions, and as space-saving devices in printed literature. It is easier and more economical to write down the acronyms HETE and RAAS than their full names 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid and renin-angiotensin-aldosterone system, respectively.

The main reason for abbreviations is said to be economy. Some actually save space in print, such as acronyms for the names of institutions and organizational units, as well as being convenient to use. Many are used for other reasons, as for instance, when trying to be delicate, we may euphemistically refer to bowel movement as BM, an unprinicipled individual as SOB, and body odor as BO. Also, it is sometimes difficult to fathom the reasoning of bureaucratic acronym makers, who have created some tongue-twisting monstrosities, such as ADCOMSUBORDCOMPHIBSPAC (for Administrative Command, Amphibious Forces, Pacific Fleet, Subordinate Command). Abbreviations and acronyms used in medicine can be grouped into two broad categories. The first consists of official abbreviations and symbols used in chemistry, mathematics, and other sciences, and those designating weights and measures, whose exact form, capitalization, and punctuation have been determined by official governing bodies. In this category, they mean only one thing (e.g., kg is the symbol for kilogram and Hz for hertz), and their form, capitalization, and punctuation have been established by the International System of Units (Systeme International d’Unites). Abbreviations in the second group, on the other hand, may appear in a variety of forms, the same abbreviation having a different number of letters, sometimes capitalized, at other times not, with or without punctuation. Moreover, they may also have numerous meanings. The abbreviation AP may mean alkaline phosphatase, acid phosphatase, action potential, angina pectoris, and many other things. Editors of individual scientific publications make an effort to standardize the form of abbreviations and symbols in their journals and books, but they generally vary from one publication to another. This dictionary lists acronyms and abbreviations occurring with a reasonable frequency in the medical literature that were identified by a systematic scanning of collections of books and periodicals at the National Library of Medicine. Except as they take the form of Greek letters, pure geometric symbols are not included. Although we have attempted to be as inclusive as possible, a book such as this one can never be complete, in spite of the most diligent effort, and it is expected that some abbreviations and acronyms may have escaped detection and others may have been introduced since completion of the manuscript. Stanley Jablonski